Why do you think He-Man, Fezzik, or Ox is a barbarian? It's not just the rage that doesn't fit, it's the outdoors stuff as well. In other words, just about everything except being big and strong. Model them as fighters or monks instead.
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mxyzplk♦Nov 11 '10 at 20:49

The best way to simulate Fezzik is with monk. Call him a brute, but the various unarmed attacks and some of the class features (suitably renamed) fit him quite well, especially with "Decisive Strike (PHB 2, p 51): Lose flurry of blows, gain ability to make one attack that deals double damage." and "Durable (UA, p 58): Gain damage reduction as barbarian. Lose speed enhancement bonus and bonus to AC (but not wisdom to AC)."

The best way to simulate He-man is with Ranger. He even has an animal companion and dual-wields.

The best way to simulate Ox, especially with his superhuman strength and durability is Psychic Warrior, fighter, or equivalent with... a depressing number of templates.

The best way to simulate Bamm-Bamm ... is with Psychic Warrior, his "hitting the floor and causing it to shake" is a great reflavouring of "Shout"

The essence is found in OOTS, where your job "title" doesn't come from your class levels.

What if you kept the mechanics but changed the way it feels - called it "Fearlessness" or "Heroic Might" or some such thing?

Or, if you don't like the limited-duration limited-uses-per-day feel of Rage, give the character a better DR bonus. I'd try one that's equal to half the character's Barbarian level (rounded down). Giving the character a flat STR bonus is probably a bad idea, but perhaps a +1 melee damage bonus, as an Extraordinary ability, that increases by 1 every time the character takes a Barbarian level that otherwise would have had a Rage ability? That would be cool in lower-level play, although pretty weak at higher levels...

Or perhaps take a look at the Berserker class in Iron Heroes. Again, by changing the name and description, you get a character that gets more dangerous the more he's being smacked around.